/*
 * Licensed to CRATE Technology GmbH ("Crate") under one or more contributor
 * license agreements.  See the NOTICE file distributed with this work for
 * additional information regarding copyright ownership.  Crate licenses
 * this file to you under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.  You may
 * obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  See the
 * License for the specific language governing permissions and limitations
 * under the License.
 *
 * However, if you have executed another commercial license agreement
 * with Crate these terms will supersede the license and you may use the
 * software solely pursuant to the terms of the relevant commercial agreement.
 */

package io.crate.sql.tree;

import java.util.Collections;
import java.util.List;
import java.util.Objects;

import static java.util.Objects.requireNonNull;

public class SimpleCaseExpression extends Expression {

    private final Expression operand;
    private final List<WhenClause> whenClauses;
    private final Expression defaultValue;

    public SimpleCaseExpression(Expression operand, List<WhenClause> whenClauses, Expression defaultValue) {
        this.operand = requireNonNull(operand, "operand is null");
        this.whenClauses = Collections.unmodifiableList(whenClauses);
        this.defaultValue = defaultValue;
    }

    public Expression getOperand() {
        return operand;
    }

    public List<WhenClause> getWhenClauses() {
        return whenClauses;
    }

    public Expression getDefaultValue() {
        return defaultValue;
    }

    @Override
    public <R, C> R accept(AstVisitor<R, C> visitor, C context) {
        return visitor.visitSimpleCaseExpression(this, context);
    }

    @Override
    public boolean equals(Object o) {
        if (this == o) {
            return true;
        }
        if (o == null || getClass() != o.getClass()) {
            return false;
        }
        SimpleCaseExpression that = (SimpleCaseExpression) o;
        return Objects.equals(operand, that.operand) &&
               Objects.equals(whenClauses, that.whenClauses) &&
               Objects.equals(defaultValue, that.defaultValue);
    }

    @Override
    public int hashCode() {
        return Objects.hash(operand, whenClauses, defaultValue);
    }
}
